why “onPause” is not called in following situation?

Question

By the document, \"onPause\" is called, when:

when the system is about to start resuming a previous activity.

Compared to \"onSt

Answer 1

This is what the official documents says about onPause()

Called as part of the activity lifecycle when an activity is going into the background, but has not (yet) been killed. The counterpart to onResume().

When activity B is launched in front of activity A, this callback will be invoked on A. B will not be created until A's onPause() returns, so be sure to not do anything lengthy here.

For detail please see this.